Heat pipes are heat transfer devices that rely on phase transition of a working fluid to transfer heat from one location to another, such as from an electronic device to a heat sink. Heat pipes may be constructed of various materials depending on an application for the heat pipe, but typically the bodies of heat pipes are constructed of a metal, such as aluminum, due to its heat transfer characteristics and density. As an example, heat pipes are often used to draw heat away from electronic equipment to prevent the electronic equipment from overheating. In some applications, thermal expansion and contraction of heat pipes due to extreme temperature changes may be undesirable.
Spacecraft include a plethora of equipment, such as electronic equipment, that generates heat. This heat must be dissipated, and because space is essentially void of air, the heat must be radiated to outer space. Spacecraft, such as satellites, typically include radiator panels that draw the heat from electronics and other equipment to an outer surface of the spacecraft. Thermal expansion and contraction of a radiator panel may affect the precision of a spacecraft's communication equipment's pointing to Earth and/or to another spacecraft or other object in outer space. For some spacecraft, the precise pointing of communication equipment is critical to its function. Historically, radiator panels have been constructed of materials that have similar coefficients of thermal expansion (CTE) so as to minimize distortions of the radiator panels due to thermal imbalance and thus to minimize the effect on the pointing of communication equipment. Additionally, radiator panels historically have been used as a ground, or power return, for electronic equipment, including communication equipment, that is supported by radiator panels. Accordingly, radiator panels historically have been constructed with aluminum honeycomb cores sandwiched between aluminum face-sheets and with aluminum heat pipes extending through the cores.